GPS Block 2R Credit - USAF

Launches began in 1997 of 'GPS-IIR' replenishment satellites, produced by General Electric Astrospace (later acquired by Lockheed Missiles & Space). The GPS IIR contract was issued in 1989 and included 21 satellites based on the commercial AS-4000 bus. These provided improved navigation accuracy and longer autonomous satellite operation than earlier model GPS satellites. Lockheed was responsible for launch and flight operations support of the GPS IIR through 2006.

Block IIR satellites provided dramatic improvements over previous blocks. They could determine their own position by performing inter-satellite ranging with other IIR vehicles. They also had reprogrammable satellite processors enabling problem fixes and upgrades in flight, increased satellite autonomy, and radiation hardness.

Additionally, the Block IIR could be launched into any of the required GPS orbits at any time, assuming a 60-day advanced notice, and required many fewer ground contacts to maintain the constellation. All of these improvements result in increased accuracy for GPS users and a cost 33 percent less per satellite than the previous generation of Block IIA satellites. Up to 12 Block IIR satellites were to be modified to radiate the new military M-code on both the L1 and L2 channel as well as the more robust civil signal L2C on the L2 channel. The M-code signal was to enable GPS operations in a higher jamming environment and reduce vulnerability of military GPS-based systems. The first modified Block IIR (or IIR-M) was planned for launch in July 2003.

The satellites were three-axis stabilized and operated at downlink frequencies of 1572.42 MHz and 1227.6 MHz (L-Band) and 2227.5 MHz (S-Band).

Design Life: 10 years. Typical orbit: 20,200 km / 12 hr period; 55 deg inclin; 6 planes. Length: 1.91 m (6.26 ft). Maximum Diameter: 1.93 m (6.33 ft). Span: 11.40 m (37.40 ft). Mass: 2,032 kg (4,479 lb). Main Engine: Star 37. Electrical System: 2 solar panels using N-on-P silicon cells. Electric System: 1.14 average kW.

• 1997 January 17 - GPS 42 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. FAILURE: T+12 sec GEM strap-on number 2 structural failure. Mass: 2,030 kg (4,470 lb).
  Destroyed in launch vehicle failure.

• 1997 July 23 - USA 132 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,030 kg (4,470 lb). Perigee: 20,132 km (12,509 mi). Apogee: 20,235 km (12,573 mi). Inclination: 55.80 deg. Period: 718.00 min.
  Placed in Plane F Slot 3 of the constellation.

• 1999 October 7 - USA 145 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,030 kg (4,470 lb). Perigee: 20,163 km (12,528 mi). Apogee: 20,202 km (12,552 mi). Inclination: 52.60 deg. Period: 718.00 min.
  Third GPS Block 2R satellite. SVN 46 replaced SVN 50 which had been damaged by rain on Pad 17 earlier while being prepared for launch earlier in the year. Placed in Plane D Slot 2.

• 2000 May 11 - USA 150 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,030 kg (4,470 lb). Perigee: 20,127 km (12,506 mi). Apogee: 20,235 km (12,573 mi). Inclination: 55.20 deg. Period: 717.90 min.
  Placed into an elliptical transfer orbit. The satellite's Thiokol Star 37 apogee motor was used to circularise the orbit at 20,000 km in Plane E Slot 1 of the constellation, replacing GPS GPS 2-1.

• 2000 July 16 - USA 151 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 20,054 km (12,460 mi). Apogee: 20,309 km (12,619 mi). Inclination: 55.20 deg.
  Global Positioning satellite, placed in Plane B Slot 5. Launch delayed from June 15 and the June 21.

• 2000 November 10 - USA 154 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 20,118 km (12,500 mi). Apogee: 20,244 km (12,579 mi). Inclination: 55.50 deg. Period: 717.90 min.
  The Delta stage 2 entered a 153 x 418 km x 37 deg parking orbit followed by a 172 x 1144 km second orbit; the PAM-D solid upper stage then fired to give SVN 41 a 20457 km apogee. The Thiokol Star 37FM solid kick motor was fired prior to November 13 to place the spacecraft in its final circular 20,000 km orbit. Placed in Plane F Slot 1 of the GPS constellation.

• 2001 January 30 - USA 156 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 20,157 km (12,524 mi). Apogee: 20,208 km (12,556 mi). Inclination: 55.20 deg. Period: 718.00 min.
  GPS Block IIR production no. SV 14. Placed in Plane E Slot 4 of the constellation.

• 2003 January 29 - USA 166 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17B. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 20,163 km (12,528 mi). Apogee: 20,352 km (12,646 mi). Inclination: 55.06 deg. Period: 720.74 min.
  Launch delayed from June 11 and August 16, 2001; March 6, April 29, August 11 and November 7, 2002.

• 2003 March 31 - USA 168 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 19,985 km (12,418 mi). Apogee: 20,376 km (12,661 mi). Inclination: 55.00 deg. Period: 717.90 min.
  Delayed from May 16, July 25, November 14, 2002, and February 6, 2003. Timely replenishment of GPS constellation.

• 2003 December 21 - USA 175 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 19,963 km (12,404 mi). Apogee: 20,328 km (12,631 mi). Inclination: 55.10 deg. Period: 716.50 min.
  Tenth Navstar Block IIR (R = replenishment) launch.

• 2004 March 20 - USA 177 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17B. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 20,100 km (12,400 mi). Apogee: 20,268 km (12,593 mi). Inclination: 55.00 deg. Period: 718.00 min.
  Launch delayed from December 19, 2003, March 8, 2004.

• 2004 June 23 - USA 178 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17B. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 20,090 km (12,480 mi). Apogee: 20,273 km (12,597 mi). Inclination: 55.10 deg. Period: 717.90 min.
  Delayed from February 17. Delayed from June 5, 11, 13, 14, 16, 18, 19, 20 and 21. Moved up from July 20.

• 2004 November 6 - USA 180 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17B. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 19,810 km (12,300 mi). Apogee: 20,413 km (12,684 mi). Inclination: 54.90 deg. Period: 715.10 min.
  Launch delayed from September 22, October 8, 25 and 30, November 5. Fired its apogee motor at around 02:40 GMT on November 9 to transfer from its initial 159 x 20380 km x 39.1 deg transfer orbit to its operational orbit in the GPS constellation.

• 2005 September 26 - USA 183 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 20,006 km (12,431 mi). Apogee: 20,187 km (12,543 mi). Inclination: 55.00 deg. Period: 714.50 min.
  Delayed from December 2004; February 1, March 17, 2005. Moved up from May 20 2005. Then delayed from May 4, July 29, August 26, September 22, 2005. Became operational at 23:30 GMT on 16 December. First GPS Block IIR-M version, which added extra navigation signals for both civil and military users. The NASA-funded L2C tracking demonstration was managed by JPL and explored the use of a new Civilian code signal (L2C). The data was collected with Trimble NetRS receivers L2C-enabled firmware. The sites were globally distributed: South Africa, Norway, Antarctica, Hawaii, and Alaska.

• 2006 September 25 - USA 190 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 20,020 km (12,430 mi). Apogee: 20,342 km (12,639 mi). Inclination: 54.90 deg. Period: 717.90 min.
  Second GPS Block IIR-M version, which added extra navigation signals for both civil and military users.

• 2006 November 17 - USA 192 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 20,206 km (12,555 mi). Apogee: 20,367 km (12,655 mi). Inclination: 54.90 deg. Period: 722.20 min.
  Set operational at 03:07 GMT on 12 December.

• 2007 October 17 - USA 196 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Mass: 2,032 kg (4,479 lb). Perigee: 20,149 km (12,519 mi). Apogee: 20,213 km (12,559 mi). Inclination: 54.90 deg. Period: 717.90 min.
  Set operational at 22:46 GMT on 31 October.

• 2007 December 20 - USA 199 - Program: Navstar. Launch Site: Cape Canaveral. Launch Complex: LC17A. Launch Vehicle: Delta. Perigee: 20,082 km (12,478 mi). Apogee: 20,283 km (12,603 mi). Inclination: 55.00 deg. Period: 718.00 min.
  Fifth GPS SV with L2C capability.

• 2008 March 15 - USA 201 - Launch Site: Cape Canaveral. Launch Vehicle: Delta. Perigee: 20,142 km (12,515 mi). Apogee: 20,223 km (12,565 mi). Inclination: 55.10 deg. Period: 718.00 min.
  The Delta's second stage first cutoff at 06:20 GMT put the stage and payload into a 174 km x 205 km parking orbit. The stage fired again to place the satellite into a 188 km x 20325 km x 40.0 deg transfer orbit. USA 201 fired its apogee motor at 09:21 GMT on 17 March in and placed itself into its operational final orbit.